Blow-off for boilers.



G. PURVIS.

BLOW-OFF FOR BOILERS.

APPLICATION FILED OCT. 21. 1914.

1,163,687. Patented Dec. 14, 1915.

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cuLmmlA PLANOGRAPH CID-WASHINGTON. D. c.

G. PURVIS.

BLOW-OFF FOR BOILERS.

APPLICATION FILED 00121. 1914.

' Patented Dec. 14, 1915.

3 SHEETS-SHEET 2.

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COLUMBIA PLANOGRAPH c0., WASHINGTON, D. c.

G. PURVIS.

BLOW-OFF FOR BOILERS.

APPLICATION FILED OCT. 21. 19x4.

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GEORGE PURVIS, OF DETROIT, MICHIGAN.

BLOW-OFF FOE BOILERS.

Specification of Letters Patent.

Patented Dec. 14:, 1915.

Application filed October 21, 1914. Serial No. 867,874.

To all whom it may concern:

I Be it known that I, GEORGE PURVIS, a citi- Zen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Blow-Oifs for Boilers, of which the following is a specification, reference being had therein to the accompanying drawings.

In the operation of cleaners for boilers known as blow-ofis, it is desirable that the disposition of the parts be such that the sediment settling at the bottom of the boiler shells be effectively dislodged over an area that is not confined to the areas of the blowoif inlets. It is also desirable that the parts be as free from packing joints and the like as possible in order that the conditions of service which are severe, do not disintegrate such packing.

This invention relates to a blow-0E for boilers having means whereby the effective area of the suction inlets is greatly increased whereby a selective action for the various inlets is obtained and whereby the use of packing is avoided.

The invention consists in the matter hereinafter set forth and more particularly pointed out in'the appended claims.

In the drawings: Figure 1 is a view in side elevation, partially broken away and in section, of one type of boiler provided with a blow-off that embodies features of the invention. Fig. 2 is a plan view of a bottom portion of the boiler showing the boiler and the blow-off. Fig. 3 is a view in longitudinal section through the lower portion of a boiler equipped with a modification of the blow-off. Fig. 1 is a View in transverse section through the boiler showing the modified form in end elevation. Figs. 5, 6, and 7 are views in detail of a selective valve shown in Fig. 1. Figs. 8, 9, and 10 are views in detail of a selective type of valve used in the modification. Figs. 11 and 12 are views in detail of a preferred form of inlet or suction member, and Figs. 13 and 1 1 are views in detail of another form of selective valve that may be used. 1

Referring to the drawings, a set of inlet suction members 1 are symmetrically dis posed or otherwise arranged most effectively in the bottom portion of a boiler drum 2 of any type at a point where the-sediment collects, Each foot or inlet consists .ofacas ing having preferably a rectangular body with an outlet nipple 3 in the appropriately design top l for connection with a suction p pe 5. The lower margins of each suc tlon plate are held at an interval from the boiler shell on which they otherwise rest by depending projections or feet 6, or they may be otherwise arranged to provide spaces between the margins and the shell on which they rest. The resultant intake slots or openmgs between the feet and the shell are so proportioned that under suction they create currents that dislodge sediment at a considerable distance from the peripheries of the feet. A valve casing 7 of any preferred type having a series of inlets and a single outlet has such inlets connected with the suction pipes 5 and its outlet in communication with the blow-01f 8 that extends outside the boiler shell where it is under control of a manually-operable valve 9. A hand wheel 10 that operates this valve 7 is located also outside of the boiler and is connected to the valve by a stem 11 which passes through suitable packing means or a stuffing box 12.

As herein shown in preferred form, the selective valve comprises oppositely-disposed casing members 13 that are appropriately secured together as by bolts 14. Outlet nipples 15 in each member are so disposed that they may be opened one at a time by the rotation of disk closures 16, each of which is keyed to the stem 11 which is rotatable in the casing members 13. The closures which are separably movable on the stem, are held to seat against the end walls of the casing members 13, preferably by steam pressure which is obtained by the employment of a blow-off pipe of less area than any one of the inlet pipes and also, if desired, by the use of a skimmer or grease pipe 17 which extends to the steam space of the boiler. Preferably such grease pipe has a suitable coupling 18 to which a floating grease trap or skimmer 19 that is kept at the level of the boiler water contents by a float 20 is connected through a branch pipe 21. In either instance, the pressure against the inner faces of the closures 16 is sufficient to hold them seated. It is to be understood that the inlet opening of the casing 14 from the grease pipe 17 is in communication with the interior of the valve casing.

In the modification shown in 3, the

symmetrical-lydisposed arrangement already described is changed by the positioning of a selective valve 21 at the boiler remote from the hand wheel 10 and blow-off valve 9, the suction plates 1 being arranged so as to draw directly toward the valve 21 from the point of greatest depth of deposit. In such instance, the selective valve may be asindicated in Figs. 8, 9, and 10 with a single closure 22 having an elongated bore 25 and an appropriate disposition of inlet nipples 23 and blow ofi pipe 21. The segmental slot indicated at 25 forms a port whereby the inlet nipples 23 or grease pipe 17 may be put in communication with the casing interior, the elongated slot permitting of the gradual opening and closing of adjacent ports without interrupting the fiow. The arrangement and disposition of the inlet or suction plates are such that the inrushing currents tend to dislodge deposits over a large area of surface around each foot, and by proper arrangement of the feet in relation to each other, the surface to be cleaned is completely controlled by the suction from the feet. As a result, a blow-off is obtained that is effective, that does not have to be shifted so that it can be used where there is little space in the engine room outside of the boiler, and that has valves which may be free from packing.

In Figs. 13 and 14 another type of selective valve is shown which consists of a casing 26 having a series of inlets 27 that are controlled by a frusto-conical closure 28 with spirally-arranged ports 29, a constantly open outlet 30 permittingthe necessary back pressure in the valve to hold the closure constantly to seat.

Obviously, changes in the details of construction may be made without departing from the spirit of the invention and I do not care to limit myself to any particular form or arrangement of parts, except as set forth in the appended claims.

What I claim as new is 1. Ablow'off for boilers comprising suction members each having an open base and margins that form with a surface to be cleaned, intake openings adapted to create intake currents of comparatively Wide extent beyond the confines of the member proper on the surface to be cleaned, an out-- let conduit, and means for selectively throwing any suction member into communication relation to a boiler to which they are ap-a plied, each having an open base and margins adapted to lie close to a surface to be cleaned and to form therewith lateral inlets which create intake currents of comparatively wide extent beyond the confines of the member proper, an outlet conduit, and means for selectively throwing any such member into communication with the outlet.

3. A blow-off for boilers comprising fixed suction members each having an open base with sidemargins that when resting upon a surface to be cleaned are adapted to form intake openings therewith that induce intake currents-of considerable velocity over an area of surface considerably greater than the opening itself, an outlet pipe, and means manually operable from a point exterior to theboiler for selectively throwing any suction member into communication with the outlet.

4. A blow-off for boilers comprising suction members adapted to be secured in fixed relation to a boiler to which they are ap-. plied, each. consisting of a casing having an open base and margins that form with a surface tobe cleaned intake openings around the periphery of the member, an outlet conduit, a valve ,for selectively throwing any suction member into communication with the conduit, and means external to the boiler for manually-operating the valve.

5. A blow-off for boilers comprising suction members adapted'to be secured in fixed relation to a boiler towhich they are applied, each having an open base with side, margins that when resting ona surface to be cleaned, form intake openingstherewith that create intake currents of comparatively wide extent along the surface to be cleaned, a valve having a single outlet-and a plurality of inlets, pipes connecting the suction members each with a valve inlet, an outlet conduit in communicationwith the valve outlet, and manually-operable means exterior, to the boiler for controlling the valve.

6. In a blow-off for boilers, .fixed suction members adapted when resting on a surface to be cleaned to form lateral intake openings therewith that create intake currents of comparatively wide extentwhereby the surfaces affectedby the several suction members are contiguous, a valve having inlets each in communication with. a suction member, an outlet conduit leading from the'valve outlet, and meansexterior to; the boiler for manipulating the valve.

7. In a blow-off for boilers, fixed suction members adapted to rest on a surface to be cleaned and. to form therewith lateral intake openings that create intake currents of comparatively wide extent beyond the confines of the members proper, a valve casing having inlets each connected to a suction member, and an outlet of less area than each inlet, closure means in the valve adapted to selectively holda-ny one inlet in communication. with the outlet, an outlet conduit leading from the va1ve outlet, and manuallyface to be cleaned on which the structure 10 operable means exterlor to the boiler for marests to form lateral inlet openings.

nipulating the valve. In testimony whereof I aflix my signature 8. In a blow-0E for boilers, a suction mem in presence of two witnesses.

.1 her comprising a casing havlng a convex upper face terminating 1n an outlet at the crest GEORGE PURVIS' thereof, and depending side walls integral Witnesses:

with the top with interrupted lower margins ANNA M. Donn,

that are adapted to cooperate with any sur- CHAS. W. STAUFFIGER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents' Washington, D. G. 

